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The alligator and its allies

Chapter 16: The Caiman
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About This Book

A comprehensive zoological study of the Crocodilia that synthesizes observations and comparative literature to describe their biology, anatomy, and embryonic development. Focusing chiefly on the American alligator as an exemplar, it surveys natural history and distribution, then presents detailed anatomical treatments of the skeleton, musculature, nervous, digestive, urogenital, respiratory, and vascular systems, and concludes with an account of developmental stages. The text combines original observations and translations with referenced sources and is supported by numerous figures and plates, followed by a selective bibliography and an index.

[6] The following figures are from an article by C. H. Stevenson in the Report of the Bureau of Fisheries, 1902, pp. 283-352.

Besides being killed for their hides, the alligators have been destroyed by the thousands merely for wanton sport, so that in 1902 it was estimated that their numbers in Florida and Louisiana were less than one fifth of what they were twenty years before that time, and unless steps be taken to prevent it, the alligator hide, as an article of commerce, may cease to exist in our Southern States.

It has been claimed that the destruction of the alligator has allowed the cane rat and muskrat to increase to a serious extent, the former doing great damage to crops, the latter often injuring the levees to a dangerous extent. Legislation to forbid the killing of alligators of less than five feet in length has been suggested and should be passed, since animals of less size have almost no commercial value for leather.

In 1902, the annual output from the tanneries of the United States approximated 280,000 skins, worth about $420,000. Of these about fifty-six per cent. came from Mexico and Central America, twenty-two per cent. from Florida, twenty per cent. from Louisiana, and the remaining two per cent. from the other Gulf States. South American hides are not handled by the United States markets.

In 1908, there were marketed from the South Atlantic and Gulf States 372,000 pounds of alligator hides, valued at $61,000.

According to the United States Bureau of Fisheries the hunter in 1891 averaged about 60 cents for the skin, while in 1902 the price averaged about 90 cents, varying between 15 cents and $2.00, depending on the size and condition of the skin. “Prime hides five feet long, with no cuts, scale slips, or other defects, are worth about 95 cents each, in trade, when the hunter sells them at the country stores, and about $1.10 cash, at the tanneries. Those measuring seven feet are worth $1.55, six feet, $1.12; four feet, 52 cents, and three feet, 25 cents. Little demand exists for those under three feet in length” (Report Commissioner of Fish and Fisheries, 1902, p. 345). Hides of seven feet are in most demand, those over ten feet are not much used. The income of the hunters is largely increased by the sale of otter, bear, deer, and other skins.

The different varieties of skins are described by Stevenson (74) as follows:

“There are several distinct varieties of alligator skins on the markets, the most important being the Floridian, Louisianian, and Mexican; each differs from the others in certain well-defined characteristics, and owing to these differences each variety has its special uses.

“The Florida skins are longer in the body—that is, from the fore legs to the hind legs—than those from Louisiana and Mexico, and consequently they are largely in demand by manufacturers of large handbags. They also have a number of so-called ‘buttons’ or ‘corn marks’ on the inside or under surface of an equal number of the scutes resulting from imbedded horn-like tissues in the center of those scales. These increase the difficulty in tanning the skins and detract somewhat from the appearance of the finished article, and for this reason the Florida skins are ordinarily the cheapest on the market. The farther south the skins are secured in Florida the greater the number of ‘corn marks,’ and those from the vicinity of Key West are almost valueless for this reason.

“The Louisiana skins differ from those of Florida in the absence of the ‘corn marks’ above noted, and from both the Florida and Mexican skins in being more pliable and in having the scales more artistically curved and shaped. Consequently they are preferred for such small articles as card-cases and pocketbooks, and usually sell at the highest prices. Skins obtained in Mississippi and Texas are similar to those secured in Louisiana, while those from Georgia and South Carolina are similar to those from Florida, except that the ‘corn markings’ are not so numerous. All the Florida and Louisiana skins show greater uniformity of coloring, being of a bluish black on the upper surface and a peculiar bluish white on the under side.

“In addition to an absence of the characteristics above noted the Mexican and Central American skins are distinguished by having from one to four small dots or markings like pin holes near the caudal end of each scale. The length of the Mexican skins varies greatly in proportion to the width, sometimes equaling that of the Florida skins. Those from the east coast of Mexico are the best, being lighter in color and with neat and attractively shaped scales. The west coast skins are yellowish in color when in the green state, and the scales are larger and not so artistically formed. The Florida and Louisiana skins are almost invariably split down the back, or rather along each side of the back, so as to preserve the under side in a solid piece, but most of the Mexican skins are split down the middle of the abdomen, keeping the back intact, making what is commonly known as ‘horn alligator.’ (See Fig. 15.)

“The skin should be removed soon after death as, in warm climates, putrefaction sets in very early and the value of the skin is depreciated. After removal, the flesh side of the skin is thoroughly rubbed with fine salt, and the skin is carefully rolled up with the salted side inside and is ready for shipment, but must be kept in a dry, cool place. Great care must be taken not to cut the hide since small cuts that are not noticeable in the raw skin may be so conspicuous in the dressed skin as to render it of much less value; a large percentage of the hides received in the markets are thus damaged.

“Formerly only the ‘belly skin’ was removed, by two longitudinal incisions just below the horny portion of the back; but it was later found that the thick horny skin of the back could be tanned nearly as well as the thinner belly skin, so that the entire skin is now usually removed by a longitudinal incision along the mid-ventral line, with lateral incisions along each leg to the foot (Fig. 15). The entire skin is more commonly taken in Mexico and Central America than in our States.

“Although the raw skins are sold according to length, the tanned hides are sold by the width of the leather at the widest part. Standard hides sell for $1.00 to $1.65 per twelve inches of width. Some skins tanned and dyed in a superior manner sell for $2.00 or more for single skins of 2¹⁄₂ feet in length. As a rule the Louisiana skins fetch the highest prices, and those from Florida the lowest. Imitation alligator leather is now prepared in large quantities, principally from sheepskins or the buffing from cowhides. These are tanned according to the usual process, and before the skins are finished they are embossed with the characteristic alligator markings by passing them between two rollers.” (Above-mentioned report, p. 346.)

Very little of the leather is now used in making shoes, the chief demand being for handbags, music-rolls, etc.

In hunting alligators for their hides two methods are usually employed, in our Southern States at least. The common method is “fire-hunting” at night; the hunters here go, either singly or in pairs, usually in boats, sometimes on foot, with shotgun and torch. The torch may be fastened to the hunter’s hat, after the manner of the miner’s lamp. One more progressive hunter that I knew had, as a torch, an acetylene lamp, attached to his hat, with the tube for the gas extending down his back to the generator in his pocket. This lamp threw a blinding beam of light far across the swamp into the eyes of the unsuspecting ’gator, which usually remained fascinated until it could be approached to within easy range. A shotgun at close range, of course, blows off nearly the entire top of the animal’s head and kills it instantly; it is then seized before it sinks out of reach and is either taken into the boat or dragged upon the bank to be collected with others in the early morning.

In daylight, with no glaring light to hypnotize it, the alligator is difficult to approach within range and it usually disappears into its cave before the hunter can get a shot at it. The daylight hunter, then, should be supplied not, of course, with a light, but with a ten- or fifteen-foot pole with a large iron hook at the end. If the alligator be vigorously prodded with this mammoth fishhook he will usually finally seize it with his mouth and can be pulled out of his hole alive. It is then an easy matter to kill him with a bullet through the base of the brain. I have seen an eight-foot alligator thus killed with a little .22 calibre “cat” rifle. An eight-foot alligator will often be all that two men can manage to drag out of his cave in this way; and, in the torrid heat of the Southern swamp, this violent exercise is not to the liking of the usually not very energetic hunter.

While the manufacture of leather gives the chief value to the alligator there are other ways in which it has some economic importance. Chief of these is probably the sale of alligator goods to tourists. In 1891 there were in Jacksonville, Florida, twelve dealers in live and stuffed alligators. In 1890, 8400 alligators were sold to tourists, the price for the live animals varying from $10.00 to $35 per hundred. For individual animals of the smallest size (less than twelve inches long) the price is usually from 50 cents to $1.00. For a three-foot alligator the price is generally $3-$5.00; for sizes over three feet $2.00 per foot may be charged, though for very large specimens the price may be from $50 to $300 each.

Besides the live and stuffed animals the teeth are polished and sold as souvenirs; about 450 pounds of teeth were sold in 1890, at a price varying from $1.00 to $2.00 per pound. From 75 to 200 teeth will make a pound.

In 1891 about forty people, in addition to the regular dealers, were engaged, in the United States, in stuffing alligators, polishing teeth, etc. The teeth are extracted by burying the head until decomposition sets in.

The tiny alligators that are most commonly sold to tourists, to be brought North, perhaps, and allowed to freeze or starve to death, may either be caught by a wire noose at the end of a fishing rod, or they may be hatched from eggs that are taken from the nests shortly before they are ready to hatch. Such eggs may readily be hatched by simply keeping them moist and at a fairly constant temperature, as has been previously noted. Besides the above uses Ditmars says: “The eggs are eaten in many portions of the South, and the search for eggs at the proper season furnishes profitable employment for many persons, as each nest contains a large number of eggs.”

Broad-Nosed Caiman. (Caiman latirostris.)

Distribution: Tropical South America.

Attains a length of about seven feet. (After Ditmars.)

(Reproduced by Permission of Sturgis & Walton Co.)

Fig. 10. Spectacled Caiman. (Caiman sclerops.) Tropical America.

The length of an adult is about eight feet. (After Ditmars.)

(Reproduced by Permission of Sturgis & Walton Co.)

Never having eaten an alligator egg I cannot speak from personal experience of its flavor; but it has always seemed strange to me that more use is not made of the flesh of the alligator. This flesh is often said to have too strong a flavor to be palatable; I have eaten it when it had no such rank taste but was decidedly agreeable, being, as might perhaps be expected of so amphibious an animal, somewhat like both fish and flesh, yet not exactly like either. Perhaps greater care should be taken in skinning an animal that is to be used for food in order that the flesh be not tainted with the musk. It may be a lack of care in preparation that has given rise to the impression that alligator meat is too strong to be pleasant. It is perhaps, also, the “idea” of eating a reptile that makes the meat unpopular. A half-grown boy, who was once in the swamps with me, had expressed a great aversion to alligator meat, so the guide, one day, offered him a nicely fried piece of alligator meat, saying it was fish; the meat was eaten with evident relish and the diner was not told until after a second piece had disappeared what he had been eating. It always seemed strange to me that the poor people of the South should not more often vary the monotony of fat pork and corn bread with alligator steaks. Whether the meat could be smoked or salted so that it would keep in a hot climate I do not know; I am not aware of any experiments along this line.

The Chinese Alligator

Beside the American form, Alligator mississippiensis, the only other species of alligator is found in China, along the Yang-tse-Kiang River; it is Alligator sinensis. It reaches a length of six feet and externally resembles its American relative; it is greenish black above speckled with yellow; grayish below.

The Caiman

This is the nearest relative of the alligator and is found in Central America and tropical South America. As seen by the table on page 2, it is usually a small animal, though one species, the black caiman, is said to reach a length of twenty feet (Fig. 10). The nasal bones do not form a bony septum as in the alligator and the ventral armor consists of overlapping bony scutes. The canine teeth of the lower jaw fit into a pit in the upper jaw, as in the alligator.

They are said by some writers to be extremely abundant in the waters of the upper Amazon, migrating to the flooded forests during the rainy season and returning to the streams on the approach of the dry season. According to Ditmars there are five species of caiman of which the spectacled caiman, C. sclerops, and the black caiman, C. niger, are the most striking. The former is so named because of the spectacled appearance due to the swollen and wrinkled upper eyelids; it reaches a length of eight feet and is said to be of a treacherous disposition. The latter has a blunt snout like the alligator and is the largest of the New World crocodilians.

The American Crocodile

Of about a dozen existing species of crocodile, but one, the American crocodile, C. americanus, is found in the United States, and it is limited to the swamps and coast of southern Florida below Lake Worth; its greater sensitiveness to cold is doubtless the cause of its not being found so far north as the alligator. Its range extends south through Mexico and Central America into South America. It was first found in Florida by Dr. Hornaday in 1875. It sometimes reaches a length of fourteen feet.

As has already been noted there is, besides certain structural differences, a marked difference in the dispositions of the Florida alligator and crocodile. While an alligator may snap its jaws, hiss, and swing its tail from side to side, it is not difficult for a couple of men with ropes and a pole to safely tie up a large specimen. The struggles of a crocodile are of a more serious nature. Ditmars thus describes an encounter with a captive Florida crocodile: “The writer well remembers his first acquaintance with a big fellow from Florida. Driven out of the crate the crocodile looked the picture of good nature. Standing away from what he thought to be the reach of his tail, the writer prodded the apparently sluggish brute with a stick to start it for the tank. Several things happened in quick order. With a crescentic twist of the body utterly beyond the power of an alligator, the brute dashed its tail at the writer, landing him such a powerful blow that he was lifted completely from the ground. As he left terra firma, an almost involuntary inclination caused him to hurl his body away from a pair of widely-gaping, tooth-studded jaws swinging perilously near. Landing with a thud on one shoulder, though otherwise unhurt, the writer threw himself over and over, rolling from the dangerous brute that was actually pursuing him on the run, body raised high from the ground. For an instant it seemed as if the crocodile would win. As the writer sprang to his feet and glanced backward, he beheld the brute throw itself flat on its belly, open the jaws widely, then remain motionless as a statue. Such is the average crocodile—an active, vicious and, above all, treacherous brute.” Ditmars says again, in the same book: “When the keepers of the reptile house of the New York Zoölogical Park clean out the big pool of the crocodilians, they actually walk over the backs of some of the big ’gators, so tame are these. They never become unduly familiar with the crocodiles, finding it necessary to pen the latter behind heavily barred gates—and in the process the men are often chased from the enclosure.”

Nile Crocodile. (Crocodilus niloticus.)

Distribution: Africa generally; Madagascar.

Grows to a length of sixteen feet. (After Ditmars.)

(Reproduced by Permission of Sturgis & Walton Co.)

Fig. 11. West African Crocodile. (Crocodilus cataphractus.)

Distribution: West Africa.

Does not attain so large a size as the Nile Crocodile. (After Ditmars.)

(Reproduced by Permission of Sturgis & Walton Co.)

In contrast to this ferocious aggressiveness in captivity the American crocodile is said to be very timid and retiring when in its native habitat.

Young animals are greenish with black marking; as they become older they are of an olive color, and old specimens are dull gray.

The Orinoco Crocodile, C. intermedius

This is a species with a very narrow snout that is not quite so large as the preceding. It is said to be abundant in the Orinoco River and its tributaries.

Besides the two above mentioned there is a small species, C. rhombifera, found only in Cuba and hence known as the Cuban crocodile.

The African or Nile Crocodile, C. niloticus

This well known and much feared species is found throughout the continent of Africa, and is very common on the island of Madagascar (Fig. 11). In the lower waters of the Nile it is now nearly exterminated. It has always been a conspicuous animal in Egypt and was one of the animals held sacred by the Egyptians and preserved by them as mummies. It is discussed by Herodotus, and the “leviathan” mentioned in the Book of Job is doubtless this crocodile. In fact the name is said to be derived from the ancient Greek for lizard, just as the word alligator is said to be derived from the Spanish for lizard—el lagarto; the resemblance in form between these big saurians and their smaller relatives is evident. The alligator, being confined to America and a small part of Asia, was probably not known to the ancients.

An excellent account of the development and habits of the present species is given by Voeltzkow (78), who says it is, perhaps, the most common vertebrate in Madagascar. The largest specimen measured by this observer was thirteen feet; Ditmars gives sixteen feet as the maximum size. This man-eating crocodile, according to Ditmars, destroys more human lives than any other wild animal of the dark continent.

The story told by Herodotus of the bird, probably a species of plover, which enters the gaping mouth of the crocodile to pick off the leeches found there may be true, since there is such a bird that may be seen perching on the backs of crocodiles, and as the Crocodilia frequently lie with their mouths wide open it is quite possible that these birds may pick off the worms that are often found within. It is also possible that the alertness of these birds to danger may serve as a warning to the crocodiles with which they associate.

Fig. 12. Salt-Water Crocodile. (Crocodilus porosus.)

Distribution: India to North Australia. Occurs at sea.

Grows to a length of twenty feet. (After Ditmars.)

(Reproduced by Permission of Sturgis & Walton Co.)

According to Voeltzkow these crocodiles dig caves of thirty-nine to forty feet length in the banks of the streams they inhabit, into which they retire on the approach of danger. The caves open under water and slope upward towards the surface of the ground where a few small air-holes are found. The natives locate the caves by means of the air-holes and dig out the hidden animal, first stopping up the entrance.

In Madagascar the eggs are laid in August and September and hatch in about twelve weeks; they are laid at night, usually shortly before daybreak. From twenty to thirty eggs are laid in one nest, which is merely a hole dug in the dry sand. As was said in connection with the Florida alligator, the habits of the two animals are quite different in this respect,—the moisture that is so important in the one case is fatal to the embryo in the other. When the eggs are laid the nest is filled in with sand so that there is nothing to indicate its position except that the female crocodile is in the habit of lying on the spot where her eggs lie buried.

Like the alligator the young crocodile makes a squeaking noise shortly before hatching and the mother doubtless opens the nest, at this time, to allow the young to escape. A fence that Voeltzkow built around a nest was repeatedly broken down by the mother in attempting to get back to her eggs.

The character of the crocodile’s egg is discussed, in comparison with that of the Florida alligator, on page 23.

The Marsh Crocodile or Mugger, C. palustris

Found in India, Ceylon, Burmah, the Malay Peninsula, and many of the islands in that region. It has a rather broad snout, and reaches a length of twelve feet. It is a timid form and is harmless to man. It is frequently venerated by the Hindoos and is kept in a semi-domesticated condition in ponds where it is fed and becomes very tame.

In the dry season when the natural ponds are empty they sometimes migrate overland in search of water, but generally they bury themselves in the mud and lie dormant until the rains begin again.

The Salt-Water Crocodile, C. porosus

This is one of the largest if not the largest of living reptiles (Fig. 12). It is said by Ditmars to reach a length of twenty feet and there is a record of one specimen that was thirty-three feet in length. It is said to be easily recognized by the prominent, longitudinal ridge that extends in front of each eye, over the prefrontal bone, and by the absence of the suboccipital scutes.

Fig. 13. Skull of Gavial.

(Dorsal View.)

(Photograph from U. S. National Museum.)

Fig. 14. Skull of Gavial.

(Lateral View.)

(Photograph from U. S. National Museum.)

 

It is typically an inhabitant of tidal waters and is sometimes found swimming at sea, out of sight of land; it seldom goes inland to any great distance from the sea. It is a man-eating species and many human lives are said to be destroyed by it in India and surrounding countries. A British “blue book” states that in British India 244 deaths were caused by Crocodilia in the year 1910.

In captivity it is savage and untamable. Ditmars, in speaking of three specimens that he had in captivity, says they were “positively the most vicious reptiles” he had ever seen.

The Indian Gavial, Gavialis gangeticus

This animal, which inhabits the Ganges and other rivers of northern India, is, with the possible exception of the preceding species, the largest of the Crocodilia; it is said to reach a length of thirty feet, which is twice that of a very large Florida alligator. As previously noted its snout is extremely long and narrow (Figs. 13 and 14), with a large, fleshy hump at the tip, that projects above the muddy water in which the animal lies concealed.

It is a timid animal and, in spite of its huge size, dashes quickly into the water on the approach of man, to whom it is seldom or never dangerous. Its Indian name, gharial, from which its generic name has been corrupted, means fish-eater, since its food consists, it is said, largely if not entirely of fish.

Considering its huge size and the character of its jaws and teeth as shown in Figures 13 and 14, it is fortunate that it prefers fish to human flesh.

Anderson (2) describes the eggs and young of the Indian gavial. He found forty eggs in a nest of sand; they were in two layers, with a foot of sand between them. The young were 15.8 inches long at hatching. He says: “The young run with amazing rapidity the moment they are out of the shell.... Some of them actually bit my fingers before I had time to remove the shell from their bodies.” The following quotation from Oldenburg (46), for which I am indebted to Dr. Hussakof, is perhaps the earliest reference to the egg of the American alligator. It also mentions the habit that is practiced by some of the recent Crocodilia of swallowing stones to aid in digestion, as was apparently done by some of the large extinct reptiles.

“The eggs of Crocodiles and Alligators are little bigger than a Turkey’s. I thought to bring one to England, but it was lost. I never broke any to see the Yolk and White; but the Shell is as firme and like in shape to a Turkey’s, but not spotted. I inquired into the Stone in the Stomach of a Cayman or Crocodile, and I found by the inquiry of a very observing gentleman there, that they were nothing but several Stones, which that Creature swallows for digestion. He took out of one a piece of a Rock as big as his head: out of others he had taken sixteen or twenty lesser. None regards them much there, whatever Monardes relateth.”